wireless: add definitions for VHT MCS support

Add definitions for the VHT MCS support values that
are used to indicate, for each number of streams
(1 through 8) which MCSes are supported.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 65c6b0f..f9c5a78 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1163,11 +1163,13 @@
  *	STA can receive. Rate expressed in units of 1 Mbps.
  *	If this field is 0 this value should not be used to
  *	consider the highest RX data rate supported.
+ *	The top 3 bits of this field are reserved.
  * @tx_mcs_map: TX MCS map 2 bits for each stream, total 8 streams
  * @tx_highest: Indicates highest long GI VHT PPDU data rate
  *	STA can transmit. Rate expressed in units of 1 Mbps.
  *	If this field is 0 this value should not be used to
  *	consider the highest TX data rate supported.
+ *	The top 3 bits of this field are reserved.
  */
 struct ieee80211_vht_mcs_info {
 	__le16 rx_mcs_map;
@@ -1177,6 +1179,27 @@
 } __packed;
 
 /**
+ * enum ieee80211_vht_mcs_support - VHT MCS support definitions
+ * @IEEE80211_VHT_MCS_SUPPORT_0_7: MCSes 0-7 are supported for the
+ *	number of streams
+ * @IEEE80211_VHT_MCS_SUPPORT_0_8: MCSes 0-8 are supported
+ * @IEEE80211_VHT_MCS_SUPPORT_0_9: MCSes 0-9 are supported
+ * @IEEE80211_VHT_MCS_NOT_SUPPORTED: This number of streams isn't supported
+ *
+ * These definitions are used in each 2-bit subfield of the @rx_mcs_map
+ * and @tx_mcs_map fields of &struct ieee80211_vht_mcs_info, which are
+ * both split into 8 subfields by number of streams. These values indicate
+ * which MCSes are supported for the number of streams the value appears
+ * for.
+ */
+enum ieee80211_vht_mcs_support {
+	IEEE80211_VHT_MCS_SUPPORT_0_7	= 0,
+	IEEE80211_VHT_MCS_SUPPORT_0_8	= 1,
+	IEEE80211_VHT_MCS_SUPPORT_0_9	= 2,
+	IEEE80211_VHT_MCS_NOT_SUPPORTED	= 3,
+};
+
+/**
  * struct ieee80211_vht_cap - VHT capabilities
  *
  * This structure is the "VHT capabilities element" as